The weapons, which would not be out of place in a James Bond film, included what at first glance appears to be a black torch with a wrist strap and the word "police" along one side. Upon closer inspection, however, one end has three holes and each contains a bullet, with a trigger mechanism in the body of the torch.

Two of the bullets remain in the weapon, which military authorities in the South said they have never seen before. Tests have shown that the flashlight-gun was accurate and the projectile was able to penetrate deep into a mattress from a distance of 16 feet, meaning it would have been lethal at short range.

The two other weapons found on the assassin, identified only by his family name of An, were an ordinary-looking ballpoint pen that contained a poison-tipped needle, while another pen was capable of firing a small projectile coated in a poisonous chemical. As little as 10 milligrams of the poison is reportedly sufficient to cause breathing problems and potentially heart failure.

The assassin had arranged to meet Park Sang-Hak in Seoul and prosecutors believe he had been ordered to kill the outspoken human rights activist.

Park, who defected from the North and now heads an organisation that regularly launches balloons across the border into the North bearing short-wave radios and messages that are critical of the regime, told authorities that he sensed something was amiss when An requested a meeting.

In the months before the apparent attempt on his life, Park's group had released balloons that called on the people of the North to follow the example of Arab states in North Africa and Middle East and rise up against their dictatorships in a Korean version of the Arab Spring.

Examining the weapons, Park told CNN, "You would notice a gun, but these weapons are so innocuous that you could easily kill someone.

"I'd be dead immediately," he said, adding that North Korea's efforts to silence him will have no effect on his activities.

South Korean police now provide Park with 24-hour protection.

An has been identified as a former North Korean special forces soldier who had been granted asylum in the South in the late 1990s after claiming he had fled the North.

News reports have suggested that he was forced to work for Pyongyang again after the regime made threats against members of his family still in the North.